Two Ways to Operate a Plate Chiller

One of the big changes in going from my old system to the Brutus 10 is the use of a plate chiller. Previously, I used an immersion chiller. Before that, I was an ice-bath guy doing extract brews.

The immersion chiller and ice bath have something in common – they cool the entire batch of wort at once.

That’s why it was strange switching to a plate chiller where you only cool a portion of the wort at a time.

But then I read the Brutus 10 plans. Surprisingly, Lonnie Mac does not pump through the Therminator in a single pass, but rather recirculates the wort back into the boil kettle until it reaches pitching temps. He doesn’t say in the plans why he does it this way, but I found this HomebrewTalk thread where he explains it:

“It works like a charm and there are MANY reasons for doing it this way…I reach the DMS Gspot in under 3 minutes and lager temps in under 20… That is all that matters. Trub is in the pot and sweet cold wort in the fermenter.”

So that got me thinking about recirculation instead of a single pass. I ended up trying both techniques. I’ll tell you later which one I prefer, but first let’s look at the advantages and disadvantages of each:

Single Pass Chilling

This is the most common way to operate a plate chiller. After the boil (or whirlpool), you drain from the kettle, through the plate chiller, and into the fermenter.

Advantages: You can cool the wort more quickly this way. How long does it take to cool? As long as it takes to empty your kettle. You can even use gravity to feed through the chiller.

Disadvantages: Accurate temperature control is more difficult. If your ground water is too warm, you will have to pre-chill it, pump ice-water, or cool the fermenter to pitching temperatures after the fact. Also, the cold break gets carried over to the fermenter.

Recirculating

This is an alternative way to operate the plate chiller. Instead of running the wort directly into the fermenter, you recirculate back into the boil kettle until you reach you desired temperature. Then you redirect the flow into the fermenter.

Disadvantages: Takes longer than single pass cooling. It requires a pump to return the wort to the boil kettle.

*This is a debated topic so I’m not ready to say it’s a sure thing. Here is what Jamil says about DMS and why his whirlpool chiller solves the problem

“DMS is often described as a cooked corn aroma that often plagues lager brewers. The thing is, the lighter pilsner malts contain more SMM (S-Methylmethionine), which gets hydrolyzed to DMS during the boil. Yes, this gets driven off, but unless you’re doing 100 minute or longer boils, there is still some SMM left behind. The neat thing is, if you can get the temperature of the wort below 140F (60C), then SMM will not be converted to DMS. The whirlpool immersion chiller will drop the temp of the wort below 140F (60C) very quickly, resulting in far less DMS in the finished beer. On the other hand, counter flow and plate chillers continue to hydrolyze SMM into DMS while sitting there at near boiling. “

What do I do?

In 5 batches on my Brutus 10 I’ve done single pass twice and recirculation three times. I prefer recirculation so I’m going to stick with that until I find a reason to abandon it. Let me explain why I like it.

The big advantage of single pass chilling is the time savings, but with recirculation I am able to cool the wort from boiling to 65°F in 15 minutes. Given the other advantages, that is plenty fast enough to go with this method.

The single pass method took 10 minutes. I couldn’t run the pump wide open because the wort wouldn’t cool enough. It would have been quicker if I pre-chilled the cooling water.

My method with recirculating is to knock the wort down to about 140°F with a garden hose. Then I disconnect the garden hose and connect my HLT which is filled with ice water. I use the second pump to recirculate the ice water through the chiller and I hit the 60’s in no time. This isn’t a new idea – it’s the one from Lonnie’s original Brutus 10 plans.

Recirculating the wort from the chiller back into the kettle

With the single-pass method, the temperature control was a real downside. It’s been a HOT summer in Denver and my ground water is around 70°F. I like to pitch the yeast right away, so bringing the wort down to pitching temps after the fact isn’t going to be a long term solution. Sure I could pre-chill the water or use ice water, but the process is still too variable. Even with an inline thermometer it was difficult to get the exact right temperature out of the plate chiller.

I like to know exactly what the wort temp is when I drain into the fermenter and recirculation gives me that level of control. Plus I can leave the cold break (at least most of it) behind in the kettle. The 15 minute chill time is also in 90°F+ heat, so in the winter it will be even quicker.

So why not use an Immersion Chiller?

Well for one I already bought the Therminator ; )

Honestly though, I do love this thing. I mean look how compact it is. With limited space, that’s a HUGE deal for me. My old 50′ immersion chiller took up 5 times the space.

Comments

I have a Blichmann Boilermaker kettle, a Blichmann HopBlocker and a Therminator. I like the recirculation method for cooling and I tried it yesterday for the first time. It didn’t take long for me to plug – I’m not sure if I plugged the HopBlocker or the Therminator, but either way it took me forever to cool because the flow through the Therminator basically stopped.

It looks like you’re having success so I’m wondering what you’re doing differently. Are you using a HopBlocker? If not, how are you filtering out your hop material?

At flameout, I remove it and put the lid on to begin recirculation. So far I haven’t had any clogs.

I’m not too familiar with the HopBlocker, but I suspect that might be what’s clogging. It doesn’t seem like recirculation would allow any additional hops to get through that didn’t get through on the first pass. My guess is that the cold break and any other material that gets through is compacting in the hopblocker. One time I did try recirculating through my hop spider bag and things got awfully backed up in there. I didn’t see the extra benefits of recirculating through there so I now remove it and just pump directly into the kettle.

Just curious, Billy… Are you using any filtration of your BK, like Lonnie? I have tried the recirculation method and it worked very well for chilling wort well below DMS temps in a matter of minutes, but I also had a false bottom in my BK to filter the hops out and prevent them from clogging the chiller. The first time I tried to recirculate without the false bottom, the rate at which the wort went through the chiller decreased significantly. I will say that I was brewing a beer with around 5oz of hops in a 5G batch, so there were a lot of hops going through the Therminator.

My only fear about not filtering out the hops and recirculating all of that hop matter through the chiller is that I’ll get even more stuff in the Therminator that I don’t want, on top of the stuff that gets trapped in there as it is (which isn’t a whole lot) with my current method (10 minute whirlpool, then hot stand for 10 minutes, then transfer to fermentor.).

I just answered a similar question for Jeff up above. I use the hop spider in that picture. You definitely need some way of filtering the hops before pumping through the chiller. It seems like a false bottom and the hop spider are the most common methods. Hop bags would probably work as well.

Billy,
I’m designing my B10 hybrid (BTW, how should I modify for Blichmann 10s). I’m not so concerned about automation (and don’t need the gas beam), but like an elegant solution. I’m going with a direct fired MT with recirculation (two pumps). Nevertheless, my question regarding recirculation through the plate chiller: It looks like you have your pump before your Therminator. Is that right? Also, what is that extension coming off your BK (past the valve) with the probe (?) and wire?
Prosit,
J.

Hey J, to modify the stand for Blichmann 10’s or any other kettle, you need to adjust the kettle supports for the diameter of the kettle. So for 10’s, you would move the supports closer together. Blichmann as the diameters on their website but personally I think it’s better to have your kettles in hand before building the stand.

Correct, the pump is before the plate chiller. You should go from the kettles directly into the pumps. The extension coming out of the kettle is a “Tee” with a thermowell connected to it. The wire is a thermocouple that goes into my control panel and hooks up to the Love controller. When attached to the boil kettle, I use it to monitor the wort temperature while cooling. More info here: http://homebrewacademy.com/brutus-10-liquid

Never mind. I think I understand your rationale after re-reading the “liquid” section of your build. I really appreciate your posting it. Could you post some detailed pictures of pump orientations/mounting?
Prosit,

No problem. I’ll try to get a close up of the pumps posted. The key thing to remember with those is to make sure that the outlet is facing straight up in the air and the inlet straight down. I had to remove and rotate one of the pump heads because they face each other, but it was easy.

You also don’t have to recirculate until you reach pitching temp. As long as you drop the whole batch under 170, you’ve stopped isomerizing alpha acids and producing DMS. Once you get below that, you can switch to pumping to your fermenter through the chiller rather than sending it back to the kettle. The colder the whole batch gets it’s diminishing returns to keep chilling it.

I use the same method, recirculating through the plate chiller into the pot. The first time I did it, though, I got a pretty weird problem. I was using my whirlpool port low near the bottom of the pot to put the wort back in after chilling, and picking it up also from the bottom through a dip tube. In no time I was at pitching temperature according to my probe (also close to the bottom of the pot). My surprise came when after putting the wort in my fermenter, thankfully a stainless conical and not glass, the temperature was over 150ºF. Why? Easy, I created a cold wort layer at the bottom of the pot, but the gradient was really deep and the temperature on the top layer was, I guess, still close to boiling. So if someone else is thinking about doing this, recirculation does not work if you put the wort back at the bottom. You have to do it as you show in that picture, putting the cool wort on the top.

Hey!
Got a question,
when we´re recirculating wort there´s huge risk of introduce some oxygen into it… I was thinkin that maybe there´s some risk when pumpin´ the wort back into de BK and maybe we´ll aereate our wort at levels that may be harmful to the beer. We all know, yeast needs oxygen in the first stage of fermentation, but my question, is there any risk of getting higher levels of oxygen into the wort?

I really think the risk of hot side aeration is overrated. As for over aerating, I’ve seen no ill effects from that. There’s really not much splashing when I recirculate though. The return arm is just above the wort and it’s a very gentle process.

A basic question: how are folks returning their wort back to the top of the BK without disrupting the whirpool cone (and clogging your plate chiller during recirculation)? I haven’t tried the recirculation method yet, just trying to visualize how this whole thing will go down.

I don’t do a whirlpool. That hop spider that I use captures almost all of the hop debris so I’ve never had an issue with clogging. I used to recirculate back through the hop spider but it backed up with wort like crazy, so now I just remove the spider after the boil and recirculate directly back into the kettle. Works like a charm.

Thanks Billy, that makes sense. I use a hop spider as well to keep the wort cleaner, but what about the hot break and cold break aggregated proteins? Once the wort is recirculated and cooled, how do you keep these out of the ferm without another whirpool/settle?

I don’t keep absolutely everything out of the fermenter but most of it settles to the bottom and I turn off the pump right when it starts to suck air. At that point there is always a thick layer of break material on the bottom.

Hi Billy, after you disconnect the garden hose and switch to the ice water, what hardware do you use to connect the hose carrying the ice water? I’m in the process of ordering all my camlocks for my brutus build. Should I add two more for this?